Covering teak deck with canvas?

[Schooner Chandlery]

Loads of good experiences related here. Thoughts--on our wood boat, our original deck (now fully replaced) was teak over fir (marine) plywood (back in the days of hand layup of plywood) it had been glassed over and painted in the 70's but still leaked along the covering boards doing quite a bit of damage to frames and whatnot. When we did the boat rebuild (2007-09) we replaced the deck entirely (deckbeams and all) which wasn't all that hard, by the way, but I digress... we had no intentions of walking on hot teak so our new deck is 3/4" Alaskan Yellow Cedar (this is the overhead) topped with two 3/8" thick BS1088 meranti plywood layers topped with an elastomeric and then nice cool painted canvas for your bare feet. Now getting to the canvas, the part I'd like to discuss since you could do it over your teak deck -- as long as you've repaired the balsa core.

Before the canvas, we "roofed" the new deck with Metacrylic -- a water-based elastomeric that we've used extensively in home renovations. It will stick to anything and once dried can be covered by tiles, flooring, or just left bare (on roof). The process is simple, you put down an openweave polyester fabric that you roll the Metacrylic paint over. When done, you use a disk sander to sand off the brush or roller marks so that it is perfectly smooth. The edges are no problem, the paint sticks like glue to the substrate. If concerned, you could run it up the edge of a coachhouse and when done with it and the canvas, cover that with a quarter round. We were lucky because we were in the middle of the rebuild, all covering boards and deck fittings were off the boat. Even the coach house (charthouse) had been lifted to allow the re-decking.

The Metacrylic is your sure-thing waterproofing and insurance policy that your deck won't leak. It's unfortunately slick as all get out (like rubber) so you have to put paint with texture or something else over it as your walking surface.

Once the Metacrylic surface is sanded smooth and cleaned it is ready for your choice of method to apply the canvas. In the USA it seems to be an east coast vs west coast thing on method to use. In the east they say bed the canvas in white lead and in the west they say to use "Irish felt" under the canvas. At the time we did our deck (2008) Irish felt was unobtainable though I tried to find it--high and low I looked. Even got a sample sent but it didn't seem quite right. We have a large deck and I didn't want to spend the bucks on sufficient white lead paste to do it properly the east coast way.

So in sort of a logical back door, I told myself "the Metacrylic is soft, it should do underneath" and went with it.

We used numbered cotton duck, untreated, and put a seam down the center of the boat. Our widest width midships required just under 14ft and we were lucky to get 84" wide duck to do the job. My husband and I had different thoughts about the purpose of the wetting down of the canvas pre-paint. There's a school of thought that the canvas should be saturated with paint and another school of thought that it should be water saturated so the paint won't penetrate and crack the canvas. Many old-timers with work boats do the paint-saturated through all the canvas route, many of today's wooden boat restoration buffs extoll the virtues of water saturation.

We flipped a coin and went with water saturation. In general we love (LOVE) the canvas deck. People come aboard and they say --it's so soft, it feels so good under my feet (with shoes on even)...what is it? It is soft, durable, cleanable, grippy because of the weave, and we have repainted it only once (last year) so...seems like the oil based paint lasts about 5 or 6 years. Having said that--we had a couple "oops" that we can hope others won't do.

On the foredeck, we did it right--we used a primer that was Zinzer oil based and the water kept it out of the weave. That was good. And we topcoated with our creamy deck color. But--little known to us, Zinzer changed their formula for that paint during our project (to comply with California VOC laws and we were in California doing the work) and our oil-based Zinzer suddenly became waterbased Zinzer. We used the New and improve Zinzer on the rest of the deck, midships and aft--guess what, it cracked. Because the water saturated canvas didn't prevent the water based paint from getting in the weave. We have tiny cracks in 2/3 of our canvas that showed up about 1 year after our application of the canvas. Even so, we love it.

Other oops -- Linseed oil base wasn't the right oil to use. We used a linseed oil based primer and paint and we are seeing a few places with mold/mildew eating the canvas from the bottom up. Linseed oil promotes growth of nasty stuff that eats it. Had we known, we might have investigated a little bit further into new (soy oil) or old tung oil formula paints or simply additives that might prevent the mildew.

I've done a couple small patches where the mold has been eating and will be doing several more this fall during our regular boat maintenance period.

Final oops? drainage leads to rot. Metacrylic will not let water through, so in a few areas (due to weight/balance) we get water sitting UNDER the canvas deck and not draining. Why? Because of a nick here or a scratch there in the paint, the canvas does let very small amounts of water through if it's been raining nonstop (like during our SE AK trip). That water finds its way to the corners of no drainage and sits and sits and sits. Next project includes installing a couple small deck drains in those areas. We have had periods of nonstop rain where after a few days, the entire canvas deck is floating atop the waterproof Metacrylic. So--the fix? If we'd gone the east coast route the white lead woudla prevented rot. If we'd gone the west coast route, the irish felt might have (or might not have) taken the brunt of the water away from the canvas -- and true Irish felt uses pine tar which, in theory, has some of it's own anti-microbial properties.

But neither east coast nor west coast we went...

As mentioned, we're planning deck drains in two areas that need it because whenever our fuel tanks are full, we rest a couple inches stern low. The other fix -- when we redo the canvas deck, we will leave a waterway between canvas deck edge and coveringboard/toerail. The waterway will just have the Metacrylic of course but we know it is waterproof. And--since we ended up with tiny paint cracks in the major portion of the install--and we've lived with them just fine, we'll probably glue the canvas down to the metacrylic with a layer of paint. Our thought is that if it rains alot, the water will exit the canvas to the wateways and overall, we will have dryer longer lasting canvas. Done the same way and at the same time as the deck, the canvas on the coach roof drains and has never had these problems (it was even primed with the water-based primer and doesn't have the cracks that the deck canvas with that treatment has) -- and it is in like new condition compared to the deck which ends up with water standing on (and then under) the canvas.

Maintenance: Paint every 5 years or so. Scrub it with SimpleGreen and a soft brush every couple months if you're in an industrial area with more than the normal grime. The seams down the middle of the boat (thread) started failing this last year, too. I cut a 5" wide strip of canvas, saturated it with deck paint and let the paint glue it over the portion of failing seam on the foredeck. Will be doing the same in a couple weeks with a portion of the mid-ships seam which is failing.

I'm putting together a how-to with resources for this decking system on Schooner Chandlery. In the meanwhile, if anyone is interested in doing a similar project, you can find the water-based elastomeric here at Metacrylic and just choose to use an oil-based paint to saturate untreated numbered cotton duck.

Best to all, Brenda

PS -- Pics of the deck...hum...that meant finding pics of the cat on deck. Here's one from spring 2014:



here's a video of our cat rolling around on deck on the canvas deck after 3 days at sea, spring 2013.

[jreiter190]

There is another method that's tried and true. You cover the deck by stretching dyneel cloth, although I don't see why canvas wouldn't serve (need a couple of extra hands to stretch and hold the cloth) while you fireMonel staples every 3" or so. This keeps the material from creeping. You then saturate the cloth with Gluvit by Travco. Gluvit has 20 per cent flex so it won't Crack and this method will make your deck like new. It also breathes, so your encapsulated teak won't rot further.A couple coats of primer and a couple coats of enamel and you're good to go. Just a suggestion from an ancient has been yacht refinisher.

[Schooner Chandlery]

Dynel is a particular weave of polyester that is meant to look like canvas, btw.

I'd heard many things about Glovit that were good and bad -- seems like an applications issue that some people ended up liking vs not. But I recently saw a boat stripped of the Glovit that had been protecting the coach roof and sides. It held moisture in and there was a lot of rot. I think it does a great job waterproofing but like many other things it does create opportunity for rot if moisture does get behind it. Not really sure how the moisture got in since I wasn't there before they started stripping off the materials.